1. Field of the Invention
The present invention relates to protective devices for bolts and, more particularly, protective guards for mine roof bolt assemblies.
2. Description of the Prior Art
Mine roof bolt assemblies, consisting of a mine roof bolt and a roof bolt plate, are well known. The mine roof bolt assemblies have been utilized for maintaining and reinforcing the structural integrity of mine roofs as well as to act as convenient points of attachment for support cables or other mining paraphernalia. In use, the bolts were implanted up to their heads at distances of up to every four feet in the mine roof; the bolt plates were fit around the bolts, in a manner similar to washers, and caused to snugly rest between the bolt heads and the mine roof to support the mine roof.
The mine roof bolt assemblies of the prior art, however, presented a serious safety defect. Mine tunnels are often only a few feet high and the bolt heads and bolt plates, which extend down from the low mine roofs, presented sharp projections which could easily injure a passing miner by causing a gash in the head, or other body portion contacting the projecting roof bolt assembly.